Mucormycosis (phycomycosis, zygomycosis) is an acute opportunistic infection caused by a saprophytic fungus found in soil, bread molds, and decaying fruits and vegetables. Numerous predisposing risk factors are associated with mucormycosis, although most cases have been reported in poorly controlled diabetics or in patients with hematologic malignant conditions. This report presents two cases of oral mucormycosis. One case occurred in the maxilla in a patient with well-controlled diabetes. The other involved the mandible and overlying gingiva in a patient with acute myelogenous leukemia. A review of the literature concerning oral mucormycosis is also presented.